Improvement in the construction of mastic roofing



UNITED STATES PATENT QFFIce.

O. O. HOFE, OF ALBANY, NEW YORK, ASSIGNOR TO E. P. RUSSELL.

IMPROVEMENT IN THE CONSTRUCTlON QF MASTIC ROOFING.

Specificationv forming part of Letters Patent No. 14,267, dated February 12, 18.36.

To all whom it may concern:

Be it known that I, C. G. HOFF, of the city and county of Albany and State of New York, have invented a new and useful Composition called and known as Hoffs Patent American Compound Roofing-Cement, for the purpose of roofing buildings in place of tin, shingles, or slate, and for other purposes; and I do hereby declare that the following is an exact description of the said invention.

This invention consists inthe following combinations and proportions each to the other for making what is called Hoffs American Gompound Cement.

The following is a specification of the various articles and combinations formingsaid cement: W'hen I want to make a new roof I use a compound made of the following substances and the following proportions: one barrel of South Carolina pitch, one gallon of rosin-oil, ten pounds of ground plaster, which is well boiled and well stirred while boiling, so as to mix it thoroughly. I then saturate canvas or cotton cloth by passing it through the above solution while hot. I then pass the canvas or cloth, while warm, through the flour of soapstone, after which it is ready to spread on the roof, and is the basis of my roofing compound.v After the roof is covered with this saturated can- "as it is prepared to receive a covering or cement made of the following ingredients: To eighteen gallons of gas-tar add one gallon of rosin-oil, one gallon of refuse oil of turpentine, one and ahalf pound copal gum, twentypounds of mineral paint, and ten quarts of the flour of charcoal. These ingredients must 'be well stirred immediately to prevent consolidation atthe bottom of the barrel until it is thoroughly mixed. This compound is then applied to the roof, previously prepared with the canvas, by spreading it over the same, forming an entire coating to the roof, over which I then spread a smaltzing of sand, rendering it impervious to water and proofagainst fire, and not liable to the action of the atmosphere, and not. liable to crack or slab oh, and at the same time airs. tight, which is not the case with some of the compounds tried for roofing purposes.

llaving thus fully described the nature of my invention, I do not claim the saturation of canvas; but- What I do claim as new, and desire to secure I 

